golang生成唯一标识id

package main

import (
	"crypto/md5"
	"crypto/rand"
	"encoding/base64"
	"encoding/hex"
	"fmt"
	"io"
)

//生成32位md5字串
func GetMd5String(s string) string {
	h := md5.New()
	h.Write([]byte(s))
	return hex.EncodetoString(h.Sum(nil))
}

//生成Guid字串
func UniqueId() string {
	b := make([]byte,48)

	if _,err := io.ReadFull(rand.Reader,b); err != nil {
		return ""
	}
	return GetMd5String(base64.URLEncoding.EncodetoString(b))
}

func main() {
	a := UniqueId()
	fmt.Println(a)
}